(1) Field of the Invention
The present invention relates to a resin-coated metal sheet with higher vivid reflectivity having the excellent workable adhesion strength, in particular, to a resin-coated metal sheet with higher vivid refelectivity having the excellent workable adhesion strength in which even if the resin-coated metal sheet is formed under the severe condition against the resin-coated metal sheet, for instance, by stretch-forming of the resin-coated metal sheet or by deep-drawing thereof, delamination does not occur so that the excellent workable adhesion strength is shown.
(2) Description of the Prior Art
Recently, decorative design of higher grade is being pursued, together with the grade of articles such as domestic electrical machinery and apparatus, audio, kitchen appliance, and interior finish materials being made higher. Decorative design of higher grade is expressed by the decorativeness of the surface of packing materials, in particular, the higher vivid reflectivity. Further, decorative design can be expressed by the shape of package which is formed by stretch-forming of the resin-coated metal sheet or by deep-drawing thereof. Accordingly, the requirement for a decorative steel sheet with higher vivid reflectivity having the workable adhesion strength fit for stretch-forming of the resin-coated metal sheet or by deep-drawing thereof is increasing.
In order to satisfy the requirement, various researches were made. For instance, there was proposed a method of laminating a colored metal sheet with a transparent thermosetting resin film or thermoplastic resin film of 5 to 100 .mu.m and a thermoplastic resin film of 5 to 50 .mu.m thickness having H to 7B hardness as disclosed in Japanese Patent Publication (Kokai) 55126 of 1991 (Heisei 2).
The vivid refelectivity can be obtained by the above-mentioned method. However, since delamination occurs in the interface between two resin component layers or the interface between laminated resin layer and colored metal sheet, the workable shape of the decorative metal sheet is limited.
Namely, in the prior art, it was extermely difficult to obtain a laminated metal sheet which has the workability fit for stretch-forming of the resin-coated metal sheet or by deep-drawing thereof and besides the vivid reflectivity.
It is an object of the present invention to provide a resin-coated metal sheet which has the workable adhesion strength fit for stretch-forming of the resin-coated metal sheet or by deep-drawing thereof, and the excellent vivid reflectivity.